This invention relates to the testing of individual circuits that supply voltages to electrically powered equipment, especially in automotive vehicles and the like wherein separate fused circuits power the various accessories. For example, there are separate fused circuits servicing the head lamp, the general lighting, the horn, the window wipers, the radio, the heater and air conditioning, and window operators, etc. In the event of a malfunction such as an inoperative actuator motor or the like, the question arises whether the fuse in a particular circuit is functioning or expended because of overloading or short circuiting. When the fuse is good and functional, then one must look to other causes of malfunctioning, which may be in a motor or accessory wiring and/or switching. Accordingly, it is a general object of this invention to provide a testing circuit for selectively determining circuit continuity through protective fuses and accessories.
Electrical equipment such as automotive vehicles are provided with fuse panels or fuse blocks, in which there are separate fuses for protecting individual circuits.
The equipment or vehicle is most often a factory produced piece of equipment, carfully wired with identified circuitry, wherein electrical voltage is applied to one side of a fuse panel, or fuse block, and wherein separately fused circuits emanate from the other side. It is an object of this invention to adapt testing circuitry to the equipment or vehicle in its manufactured condition, without change. Accordingly, a fuse adapter is provided that interrupts the individual fuse circuits, whereby each fuse is disconnected from its accessory circuit for testing. It is also an object to reconnect each selected fuse circuit to a battery terminal for normal "ON" operation protected by an accessibly replaceable fuse. It is still another object to provide an "OFF" condition of the test circuit when applied to a selected fused circuit and its accessory.
State of the art practice places fuse panels, or fuse blocks, in hard to get at and difficult locations, it being an object of this invention to extend the adapted fuse panel wiring to an accessible location, as for example to the face of the equipment panel, or to the face of the vehicle instrument panel.
The state of this art is ever changing, with the use of various types of fuses. The conventional and widely used cartridge type fuse is shown herein, however it is to be understood that this does not preclude the use of other types of fuses, such as prong or blade contact fuses and those of plug-in configuration, nor are circuit breakers to be excluded. The present invention provides an adapter that connects into the fused circuit to be tested. Accordingly, it is an object of this invention to provide selective switching means by which a multiplicity of separate fused circuits are maintained in individual electrical continuity, with the exception of one selected circuit to be tested. To this end a progressively operable selector switch is provided with one pair of contacts reserved for the testing circuit that determines continuity through the fuse and/or through the related accessory.
Fuse adapters are provided to be inserted into each electrical circuit to be tested. Each adapter is connected to an indentifiable input terminal on a selector switch which has corresponding output terminals to each identifiable accessory circuit. The electrical continuity circuit means as it is later disclosed herein, has a mode selector switch by which fuse continuity is tested, and by which accessory continuity is tested directly through a fused circuit from the main power supply, the battery.